In recent years, traffic from mobile telephones is growing steadily, and this trend is increasingly apparent as smartphones become prevalent. Responding to the increasing traffic, telecommunication operators not only reinforce the facilities of existing macro base stations, but also set up at hotspots small-sized base stations called picocell or femtocell, which have smaller coverage areas, thereby attempting to create environments where users can perform communication with comfort. Moreover, femtocells are set up not only at hotspots but also indoors, such as at home or in companies where the radio waves from macro base stations hardly reach, whereby they are used to increase users' convenience and to provide value-added services exploiting their locality.
A procedure for a HeNB (Home eNB) to acquire network information of a Universal Mobile Telecommunication System terrestrial radio access network (hereinafter, UTRAN) or a GSM EDGE radio access network (hereinafter, GERAN) is referred to as RAN Information Management (hereinafter, RIM) and is defined in NPL 1. In RIM, a HeNB inquires about network information of a UTRAN/GERAN by using S1AP:ENB DIRECT INFORMATION TRANSFER, which is sent to a MME (Mobility Management Entity). This message is sent to the UTRAN/GERAN via the MME and a SGSN, and the UTRAN/GERAN having received this message sends a message in which its network information is set to the SGSN. The HeNB acquires the network information of the URTAN/GERAN through S1AP:MME DIRECT INFORMATION TRANSFER, which is received from the MME.
A procedure for a HeNB to specify the TNL (Transport Network Layer) address of an eNB or a HeNB (hereinafter, collectively represented as (H)eNB) whose TNL address should be used to establish a SCTP (Stream Control Transmission Protocol) connection but is unknown is referred to as TNL address discovery and is defined in NPL 2. A HeNB sends S1AP:ENB CONFIGURATION TRANSFER to a MME in order to inquire about the TNL address of a (H)eNB, and the MME, if it manages the (H)eNB, or, if not, another MME managing the (H)eNB, after the MME transfers the message to the another MME, sends S1AP:MME CONFIGURATION TRANSFER to the relevant (H)eNB. As a response to this, the MME receives S1AP:ENB CONFIGURATION TRANSFER from the relevant (H)eNB. The originating HeNB receives S1AP:MME CONFIGURATION TRANSFER from the MME managing the HeNB itself, thereby acquiring the TNL address of the (H)eNB.
There is another procedure similar to the above-described TNL address discovery procedure, called HNB Configuration Transfer, which is performed by nodes, namely HNB (3G Home NodeB) and HNB-GW, in a UTRAN network and is described in NPL 3. A HNB acquires the TNL address of a neighbor HNB through the HNB Configuration Transfer procedure as in the TNL address discovery procedure. In this procedure, a HNB-GW does not send a message to an upper-level network than itself. This point differs from the TNL address discovery procedure, in which a message needs to be sent to a core network.